Electrical regulation for electric motors.



B. MOINNBRNEY. ELECTRICAL REGULATION FOR ELECTRIC MOTORS.

APPLICATION FILED 11116.26, 1911.

Patented July 8, 1913.

UNITED STATES. PATENT OFFICE;-

BENJAMIN MCINNERNE QF c ouncrL. BLUFr's, Iowa.

ELECTRICAL REGULATION FOR. ELECTRIC orons.

To all whom it may concern;

Be it known that. I, B N AMIN "MoIuseam-1r, acitizen of the United-States, re-

. siding at Council Bluffs,

5 lottawattamie, State of Iowa, have invented a new and useful Electrical Regulation for Electric -Mot0,rs, of wh'ich the followingis My invention relates to improveineiit, in

regulation of electric motors wherein the re- SlSttlHCC lfl the motor circuits is varied and the object of my improvement is to automatically rcducethe-spced of'an induction motor, either when acting against or with the load. I

' It is well knowirthat introducing resistance intothe secondary of an induction motor will-tend to reduce the speed, it the motor is operating against the load, it will 0 also tend to cause 'themotor to race'where the conditions are such. that the load tends I to drive themotor. v

My invention is designed to overcome-this difficulty.

I attain these objects by the structure and mechanism illustrated in the'accompanying drawing in which, 3 the figure is a sidecleva tiou of anyordinary induction motor with- Y L- a'suspcnded load and a diagram of circuits,

switches and resistances.

Similar letters refer to similar parts tl'iroughout the several views.

' m, is any ordinary induction motor hav ing a. phase wound rotor secondary, and a 3 stationary primary which isv supp'lied with alternating current through the leads, a, b,- and 0. Here shown for convenience, as a threephase motor thoughmy invention is equally applicable to motors wound for any number of phases.

d, represents any means of applying a load to the motor, here shown as a winding drum with the load w, applied in the form ofaweight. The secondary circuits of the induction motor are brought out through the usual slip rings and the connections 9, f, and e, hereheing shown as a. three-phase circuit but which may be varied to adapt it to the phase employed with the motor. In the circuits formed through the connections, 9, f,

' and e, are

placed. uitable ,4 bistances, t, "n, and 0.

s, is,a switch of any suitable form adapted '55 to short circuitthe resistances 1,41,, and 0,

here shown as accomplishing this by the Specification of Letters Patentf in, the county of f I 7 hold 1'. In' the lead a, ispl aced u m, and in the leads,lb 0,?"si1riilar-solenoids solenoid x, will be energized closing the ratenteduui a' aia Manama August 26,1911; Se1'ialN0.646;282.

solenoid m,- iwhich when energizedactiiates' the switch 8. Connected to operate with} j the switch .5, is the switch I whih is adapted I to open and close'a circuit'throu h the sole'-; '50

"solenoid are shown respectivelyfizf-antij fl hesole no ds o, u, and q, operate .the'swteh 1*,Jwhichis in parallel with switch I-he'Kc" )r 1trolling;"65

switch is placed in a circuit'takerffro h two of the leads, as t'ffll 'd 'b, through "the' solenoidir, operatingthe switch Z, and the switch 8. I

1c, isany suitable retardingmechanismin ,70' this instance, shown as a rshoe brake --applied to a rotating part meansfofa spring 3 and adapted to be released-bythe solenoid i, or similar means. v

W hile here illustrating my invention b -a '.threephase motor, it is'obvious that my in;

vention can be applied to motors'h'aving-any number of phases. -'It will also be obvious that the switch 1', may be operated by a solenoid inth'e ci'rcuitiof one. lead 'onljrjjbat 'I prefer to balance the circuits by inserting I a solenoid in each lead. Current'is supplied to theleads, a, b, and c, from any usualsource. Assuming that such current is sup plied in the leads, a, b, and-c, topperate the -motor to raise the load co, the solenoidsfin a, and. q, will energized, and'wh'en the current in the primary. becomesstrong enough to operate the switch r,.will close the circuit through ;.the solenoidi, releasing the retarding brake Then the load will be lifted at a speed determinecl'by characteristics of the. motor including the resistances 0, n, and t, in the secondary. Assuming that such current is supplied in,95

the leads, (i, b, and c, to operate the motor to lower the .load 10, the first inrush of current may be sufiicient to close switch r, and release retarding bralc'e lc,.butimmediate1y thereafter, the action of the load will tend to reduce the current in the primary of motor, until switch 1*, opens and the retarding brake is, is applied tending to decrease the speedf To increase the speed of the motor m, the operating switch 7;, is "closed, the

switches a, and], short circuiting the ref. sistances 0, n, and t, and releasing the re tarding brake is, as heretofore described. Then when said switch p, remains closed, [10 the speed of the motor will becontrolied I by its own ce nter-electromotive force,

either when running with or against the load, and regardless whether the switch 1', is open or closed.

It is evident that the retarding brake is,

is notlimited to the form of drum and shoe shown, but may consist of anyretarding means controlled by, switches r;;and Z. It is also evident that my invention may be similarly applicable to motors in which the speed is varied by other means, as by varyingthe impressed voltage i'n'lthe priters Patent is:

15' 1. The combination of anj-induction mo:

mary. p VVhatI claim and desire/to secure by Let;

tor; av resistance inithe secondary ofsaid motor; a' means for yarying the resistance in saidseco-ndary ,of said motor; aswitch actuated 1 by series solenoids" i'nj' the motor circuit; a switch in parallel with said first named switch and actuated coincidently I witlrthe'means for varying the resistance in named "switch and, act-hated .coincidently with the means for varyingthe resistance in said secondary; a meansfor retarding the said secondary,'and a means for retarding V actuated by series solenoi s in the motor circuit; a switch in parallel with said first said motor, the said'retardingmeans being varied by the operation of the said switches in parallel, and an operating switch adapted to control the means for varying the -re-' sistance in said secondary of said motor.

' BENJAMIN MoIIINERNQE]Y.

Witnesses:

-HE1IRY PE'rEns0N,' V EDNA VVATERMAN;

Copies of this pat ent m'ay be obtained for five cents each, by addressing'tlie. Commissioner of Yatentgv Washington, no." 

